Investigation of beam self-polarization in the futuree+e−circular collider

E Gianfelice-Wendt

doi:10.1103/physrevaccelbeams.19.101005

Abstract

The use of resonant depolarization has been suggested for precise beam energy measurements (better than 100 keV) in the $e^{+}e^{-}$ Future Circular Collider (FCC-$e^{+}e^{-}$) for Z and WW physics at 45 and 80 GeV beam energy respectively. Longitudinal beam polarization would benefit the Z peak physics program; however it is not essential and therefore it will be not investigated here. In this paper the possibility of self-polarized leptons is considered. Preliminary results of simulations in presence of quadrupole misalignments and beam position monitors (BPMs) errors for a simplified FCC-$e^{+}e^{-}$ ring are presented.

Highlights

A hadron collider of 100 km circumference and 100 TeV in the center of mass is under study by the international physics community as energy frontier Future Circular Collider (FCC)
The aim of this paper is to present results of preliminary investigations on the level of polarization attainable in FCC-eþe−
In this paper studies are presented for a FCC-eþe− “toy” ring consisting of 1064 Focusing-Open space–DefocusingOpen space (FODO) cells with dipole bending radius of ρd ≃ 10424 m and four dispersion free regions for accommodating wigglers

Summary

Introduction

A hadron collider of 100 km circumference and 100 TeV in the center of mass is under study by the international physics community as energy frontier Future Circular Collider (FCC). The same tunnel could host first a lepton collider, FCC-eþe−, with beam energy ranging between 45 and 175 GeV, cost-effectively combining the TripleLarge Electron-Positron collider and Very High Energy Large Hadron Collider proposals [1]. Resonant depolarization has been used with this purpose for the first time at VEPP-2M [2] and more recently at Large Electron Positron collider (LEP) [3]. The aim of this paper is to present results of preliminary investigations on the level of polarization attainable in FCC-eþe−. The energy calibration scenario for FCC-eþe− is described in [4]

Objectives

Results

Conclusion